> ## Documentation Index
> Fetch the complete documentation index at: https://docs.buzzkit.dev/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> BuzzKit is an open source notification orchestration layer. Send mobile push from a backend with one POST to /v1/messages, targeting a subscriber id, a topic, a saved segment or an inline expression. Subscribers are addressed by the caller's own user ids. Authenticate with a bearer API key from the dashboard; workspace keys pick a tenant with the BuzzKit-Tenant header. Every response is the envelope { success, data, error, metadata } and errors carry a stable snake_case code. iOS is the supported client SDK. The machine-readable API description is at https://buzzkit.dev/openapi.json.

# Introduction

> One API for sending, targeting, scheduling and automating mobile push on your own APNs and FCM credentials.

BuzzKit sends, segments, schedules and automates mobile push through a REST API, a dashboard and an iOS SDK, using your own Apple and Firebase credentials. Run it hosted on buzzkit.dev or self-host the same codebase.

## Identify, then send

Identify a subscriber with your own user id, then send. BuzzKit answers 202 with a message id, works out which devices are reachable, fans out through a durable queue with retries, and records every attempt per device.

<CodeGroup>
  ```bash Identify theme={null}
  curl https://api.buzzkit.dev/v1/subscribers/user_42 \
    -X PUT \
    -H "Authorization: Bearer bk_ws_..." \
    -H "Content-Type: application/json" \
    -d '{ "attributes": { "name": "Maya", "plan": "pro" }, "timezone": "Europe/Berlin" }'
  ```

  ```bash Send theme={null}
  curl https://api.buzzkit.dev/v1/messages \
    -X POST \
    -H "Authorization: Bearer bk_ws_..." \
    -H "Content-Type: application/json" \
    -d '{ "to": "user_42", "title": "Leg day", "body": "6:00 with Maya." }'
  ```
</CodeGroup>

<CardGroup cols={2}>
  <Card title="Sending" icon="paper-plane" href="/sending/messages">
    Target one subscriber, a topic, a saved segment or an inline expression, with retries and a full delivery ledger.
  </Card>

  <Card title="Scheduling" icon="clock" href="/sending/scheduling">
    Hold a message until a moment, in a fixed time zone or in each subscriber's own.
  </Card>

  <Card title="Segments" icon="filter" href="/audience/segments">
    Saved, versioned conditions over attributes, events and activity, evaluated at send time.
  </Card>

  <Card title="Workflows" icon="diagram-project" href="/automation/workflows">
    Versioned specs with waits, branches, loops and fetches that run per subscriber.
  </Card>

  <Card title="Topics and preferences" icon="bell" href="/audience/topics">
    A notification settings screen for your app with no backend code.
  </Card>

  <Card title="Multi-tenancy" icon="layer-group" href="/platform/tenants">
    A tenant per customer, each with isolated subscribers and credentials, behind one key.
  </Card>
</CardGroup>

## How it fits together

Your backend calls the API with a workspace key. A **workspace** holds your team and billing; a **tenant** inside it is the isolation boundary that owns subscribers, credentials and sends. Simple apps use the default tenant and never think about it. A platform sending for its own customers gives each customer a tenant and picks one per request with a header.

Your app embeds the iOS SDK with a client key. The SDK registers the device, identifies the user by the id you already use, and tracks events. Those events feed segments and trigger workflows.